Aircraft comprise complex wiring systems for the transmission of power and control signals between the various components and systems of the aircraft. Conventionally, these electrical components/systems are connected by cables routed through the aircraft structure. These cables are conventionally fastened within cable raceways, which are elongate metallic ducts comprising one or more channels in which the cables are retained. The raceways serve the purpose of guiding and securing the cables, protecting the cables from mechanical damage and also protecting them from electro-magnetic hazards (EMH), which include various electrical interferences and threats such as electromagnetic interference (EMI), electromagnetic coupling (EMC) and radio frequency interference (RFI).
The cables may also be provided as an over-braided cable harness, which comprises a bundle of cables within a protective sleeve, of a material such as Nome™, Kevlar™, nylon or other suitable material, and an outer braided metallic mesh. This provides the cables with both mechanical and electrical/EMH protection. The cable harness may then be secured by clips that retain the harness to the aircraft structure or within a raceway.
Such cable harnesses for the transmission of power and signals comprise a large number of components and a high weight of materials and also occupy a large volume of space on or within the vehicle structure. For example, the electrical raceways require mechanical fastening to the vehicle structure, the cables must be fastened within the raceway by clips or other suitable fasteners, and a minimum spacing must be provided between the harness and any conductive (e.g. metallic) structure to which the harness is attached, to reduce the risk of electrical arcing between the harness and the conductive structure should a cable become fretted and the conductive inner wire exposed. The complexity of these cable arrangements also results in a long installation time in the vehicle construction process, and a complex installation process.
In certain areas of an aircraft, cables must be routed externally, such as on the wings where fuel tanks are located. Here, since cables may not pass through the fuel tanks for safety reasons, yet power is required for the fuel pumps within the tanks, the power cables must be provided on the underside of the wing, and then covered with a fairing for environmental protection of the cables and aerodynamic performance of the wing. Again, this is a complex arrangement with long installation time as part of the aircraft construction process, and also results a number of relatively large additional fairing structures being disposed on the underside of the wing, reducing aerodynamic performance.
It is desirable to provide a vehicle fairing and electrical routing that substantially alleviates or overcomes one or more of the disadvantages mentioned above.